What is the measure of angle Q?

50 people men and women were asked if they watched at least one sport on tv. 20 of the people surveyed are women, but only 9 of them watch at least one sport on tv. 16 of the men watch at least one sport on tv. make a a two-way table and a relative frequency table to represent the data.

Which geometric principle is used to justify the construction below?

Determine the area of a triangle with (see picture below)